I noticed after the 12/11 update that the big picture overlay is absent while playing some of my games. Two examples being Sine Mora, where it defaults to the normal steam overlay, or Skyrim, where there is no overlay at all, big picture or normal.

So far I've tried to reset steam to default settings and to a repair install with no luck. I'm afraid of doing a complete uninstall knowing I might have to reinstall all of my steam games as a result, but they were all working just fine before the update so maybe that's what they need.

Not sure if anyone else is having this issue but hopefully someone can help.